1. Field of the Invention
The present invention is generally in the field of semiconductor fabrication. More particularly, the invention is in the field of semiconductor die fabrication and packaging.
2. Background Art
A semiconductor die can be surface mounted to a package substrate employed to house the die by using flip chip technology. In flip chip technology, the semiconductor die is “flipped” over so that the active surface of the die faces the package substrate. Electrical contact between the semiconductor die and the package substrate is achieved through solder bumps (also referred to simply as “bumps” in the present application) that are placed on the active surface of the semiconductor die. In a conventional “flip chip,” each semiconductor die pad (also referred to simply as a “pad” in the present application) situated on the active surface of the die is connected to its corresponding unique bump using a pad-to-bump routing layer on the die. The semiconductor die also includes a core, which can include different types of interfaces, such as digital and analog interfaces.
In a conventional semiconductor die, each interface in the core is typically coupled to corresponding pads and bumps on the active surface of the die. However, some applications may require selection of one type of interface in the semiconductor die, such as a digital interface, and other applications may require selection of a different type of interface, such as an analog interface. An unselected interface (also referred to as a non-preferred interface in the present application) in a conventional semiconductor die is typically disabled at the package level. However, in the conventional semiconductor die, an unselected interface is still coupled to bumps on the die, which are unused. Since the manufacturing cost of a semiconductor die is generally determined by core area and the number of pads and bumps, any unused bumps corresponding to an unselected interface increase the bump count on the die, thereby undesirably increasing manufacturing cost.